Railway signaling.



'R. A. MCCANN.

RAILWAY SIGNALING.

- APPucAndN men AUG.'I9, 1914. '1 ,271,592, Patented July 9, 1918.

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RONALD McCANN, OF NEW BRUNSWICK,

E STATES ATE NEW JERSEY, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY SIGNALING.

Specification of Letters Patent.

Patented July 9, 1918.

Application filed August 19, 1914. Serial No. 857,432.

To all whom it may concern Be it known that I, RONALD A. MoGANN, a citizen of the United States, residing at New Brunswick, in the county of Middlesex and State of New Jersey, have invented certain new and useful Improvements in Railway Signaling, of which the following is a specification.

My invention relates to railway signaling, and particularly to signaling for stretches of singletrack over which trafiic moves in both directions, such for example, as stretches of single track between passing sidings.

I will systems embodying my point out the novel claims. 1 I

In the accompanying drawings, Figure 1 is a diagrammatic view showing a stretch of track having applied thereto one form of signaling system embodying my invention, the signals being of the two-position type indicating clear and danger. Fig. 2 is a view showing a modification of the circuits shown in Fig. 1.

Similar reference characters refer to similarparts in each of the views.

Referring first to Fig. 1, A B is a stretch ofsingle trackbetween two passing describe two forms of signaling invention, and will sidings E and F, over which stretch trafiic moves in both directions. Traflic through this stretch from east to west is governed byv signals S, east is governed by signals S and S As here shown, signals'S and S are located at the entrance ends of the stretch, while signals S and S are located at intermediate points in the stretch and are staggered in relation to each other.

Insulated joints 1 divide the stretch A -B into several successive sections AC, (3-D and D-B, and as here shown the intermediate signals S and S C and D respectively. Each section is further divided by insulated joints 1 into two sub-sections, as A-II and H C for section AC, and each sub-section is provided with a track circuit. Each track circuit comprises the rails of the sub-section, a battery 6, and a features thereof in and S and trafiic from west to.

are located at points A signal relay is provided for the control of each signal and designated by the refer ence character R with an exponent corre sponding to the exponent of the signal which the relay controls. Each signal is provided. with a circuit which is controlled by the corresponding signal relay. For example, the circuit for signal S is from battery P through wire 73, contact 3 of relay R wire 4:, mechanism of signal S wire 5, contact 6, wires 7 and 8 to battery P The circuit for each of the other signals-is similar to that just traced for signal S Signal relay R for signal S by contact 35 of signal relay R and signal relay R is provided with a circuit which is controlled by each of the track relays for the sections in advance of thesignal S and also by a back-contact of an auxiliary relay X. The circuitfor signal relay R is from battery P through wire 112, contact 113 of track relay T wire 114, contact 115 of track relay T wire 116, back contact 117 of relay X wire 118, contact 119 of track relay T, wire 120, contact 121 of track relay T wire 122, relay R wire 123, and common wire 0 to battery P Signal relay R for signal S is similarlyocontrolled by a contact of relay R and the latter relay is similarly controlled by each of the vtrack relays for the sections in advance of signal S.

Thecircuit for signal relay R is provided with a branch around contact 35' of relay R which branch is controlled by an auxiliary relay X similarly, the circuit for relay R is provided with a branch around contact 97 of relay R which branch is controlled by auxiliary relay Xt; Each auxiliary relay is controlled by a pick-up circuit and a holding circuit. The pick-up circuit for auxiliary relay X is from battery P through wires 78, 58' and 88, contact 46 of track relay T wire 87, contact 47 wire 86, relay X wire 80, to battery P The holding circuit for this. relay is'from battery P through wires 73 and 58, contact 79 of track relay T wire 78, contact 39 of relay X wire 64, relay X and wire 80 to battery P Thiszholding circuit is provided with a branch around contact 79 of track relay T which branch is from wire 58 through wire 50, contact 47, wire 81, to wire 78. By virtue of this branch, it will be seen that the holding. circuit of relay X remains'closed as long as signal S remains in the danger position.

is controlled tracker-clay? will be --'op e'ned",- and-fltracli relay T i will close, buttheposition ofnthi cause the circuit for relay R -isopen at the hence relay X 1, but'thecontrol of-the signal relays is wires 73and 83, contact changes to danger. The opening of track relay. T:- :also :opensrtheicircuitfor signal relay It-i ati-iconta'ct ltg thus fcausingsignal S toc'go: :toI-uthedanger: position". The opening-1 of: signal relay R 0pens the circuit for sigdangers-position; v V the:train moves into sub-section N--D,

nalfire'layi R thus: puttingsignal1S .t'o-the" signals will not change since thesignal relay circuits controlled by -.these' two relays are; the. same. The opening of track relay T auxiliary relay; Xi r As the train-enters sub-section D Q, track relay T opens, thus causing relay R toopen, thereby allowingsignal S to change to clan ger. The opening of trackrelay T closes;

the holding 'circuit'for relay X so the latter remains closed evenrafter track relay T closes. V Assoon as track relayTiis picked up, relay R becomes energized by a circuit from one side of battery P 84 of auxiliary re lay Xflwire 68, contact 18 of track relay T wire '70, cont'act 45 of track relay T, relay R wire-72, and commonreturn wire 0 to the other side of batteryeP Upon the closing ofsignal relay-R signal S will change to the clear position thus allowing a following Westbound train to enter subsection Bl l. As the first train passes through the remainder of the'stretch it holds open the circuitfor re1ayR by one oranotherbftrack relays T ,.T or T ,'hence signal S continues to indicate danger.

Auxiliary relayX continues tobeclosed as longas signal S indicates danger, because of contact 47operated-by this signal, hence' signal S :continues at clear unless a following train enters the stretch. As the train enters section"C H it closes at the contact of relayT the pick-up circuit for relay X,

but this circuit is then open at contact 47 of signal S, and this signal is at danger beback contact of relay X does not close.

The-operation of the apparatus shown inf Fig. 1 during the movement of a train throughthe stretch from west to east would be similar to the operation just explained.

"Referring'now to Fig. 2, the arrangement of signals here shown is the same as in Fig.

similar to those ust traced for closes at contact 46ft 'he pick-up circuit for* through bound car or train.

somewhat different. In Fig. 2 the signal .R for the eastbound signals are also connected in multiple and are energized from battery P. For example, the circuit for relay'R i's 'from battery P through Wire 89, contact 92 of track relay T wire 93, contact 94 of track relay T wire 95, back contact 97 of auxiliary relay X 9 wire 98,.conta'c ta99 of 1 track relay: T4,. wire? 100; contact 101 of track fre'layiT Wire 102; relay 'R ,"-Wiref124, a-nd tcoinmon Wire 0 to battery P The circuit 'i or: relay R -leaves rtliisi circuit at wire 102 and passes througliawirex103,-=back'point ofr: contact 84 of'auxiliaryfrelay X wire 104, contact 18 of track relayi-Tffyvire 70, contact45 of track:relay T, wire 71, relay R,"and wire -74 tocommon wire 0.. i

Auxiliary relayX is arranged when energized todisconnect relay R fromthe multiple circuit justtraced' and to connect it with battery P and similarly relay X is air ranged'when energized to disconnect relay R from-its multiple circuit and to connect this relay with battery P These auxiliary relays X and X are andltoldingcircuits which are similar to those previously traced herein for theaux iliary-relaysin Fig. 1..

The operation of the apparatus Fig. 2 is as follows: V

As a westbound. car or train enters subsection B N,it opens track relay T, thereby opening relay R and causing signal S to change to danger. The opening ofltr'ack relay T also opens the multiplecirc'uitin eluding signal relaysR and R*, so that signals S andS" change to danger.-. Asthe train: proceeds into sub-section ND, it causes no change in the signal indications, but it closes the pick-up circuit for auxiliary relay X whichrelay then closes. Thenas the train proceeds into sub-section DQ, the opening of track "relay T opens signal relay R3, so that signal S lays X and T being now-closed, relay R is energized from battery P so that signal S changes to clear, thereby permitting a fol-. lowing westbound train to enter the stretch. Asthe trainproceeds through the remainder of the stretch it holds signal relay R opened by one or another of track relays T4,.T or T ,.sothatsignal S continues to indicate danger, and auxiliary relay X continues to be closed byvirtue of contact 47, so that signal S continues in'the clear position unless a following westbound train enters the stretch- "The operation of the apparatus shown in Fig. 2 during the passage of an eastbound car or train through the stretch is the same as the operation of the passage of a westshown in provided with pick-up.

changes to danger; Re-

Although I have herein shown and described only certain forms of railway signaling systems embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track, track circuits for the stretch including track relays, two end signals for governing traffic into said stretch from opposite directions, two intermediate signals located respectively in advance of said end signals, a signal relay for each signal, a circuit for the signal relay for each end signal which circuit is controlled by the signal relay for the adjacent intermediate signal and by the track relays for the stretch between said two signals, a circuit for each intermediate signal relay controlled by the track relays for that portion of the stretch in advance of the intermediate signal, an auxiliary relay for each intermediate signal relay for rendering said relay ineffective to control the end signal relay in the rear; a pick-up circuit for each auxiliary relay including a contact operated by the adjacent intermediate signal and closed when the signal indicates clear, and a back contact of a track relay in the rear of said signal; and a holding circuit for each auxiliary relay including a back contact of a track relay in advance of said intermediate signal, and a front contact of the auxiliary relay.

2. In combination, two successive sections of a railway track, two signals located respectively adjacent the entrance ends of said sections, track circuits for each section including track relays, a signal relay for each signal, means for controlling the signal relay for the rear signal by the track relays for both sections and for controlling the signal relay for the signal in advance by the track relays for the section in advance, an auxiliary relay for removing the signal relay for the section in the rear from control by the track relays of the section in advance, a pick-up circuit for said auxiliary relay controlled by the signal relay for the section in advance and by a back contact of the track relay for the forward track circuit of the section in the rear, and a holding circuit for said auxiliary relay controlled by the auxiliary relay itself and by the signal relay for the section in advance.

3. In combination, two successive sections of a railway track, two signals located respectively adjacent the entrance ends of said sections, track circuits for the sections including track relays, a signal relay for each signal, means for controlling the signal relay for the rear signal by the track relays for both sections and for controlling the signal relay for the signal in advance by the track relays for the section in advance, an auxiliary relay for rendering the track relays of the section in advance ineffective to control the signal relay for the section in the rear, iary relay controlled by the signal relay for the section in advance and including a back contact of a track relay for the section in the rear, and a holding circuit for said auxiliary relay controlled by the signal relay for the section in advance.

4. In a signaling system for railways, in combination: a trackway divided into track circuited blocks each having a track relay; a signal for governing the traffic in one direction over said trackway; a circuit for controlling said signal; means controlled by the track relay of the block following the block protected by said signal for controlling said signal controlling circuit; an auxiliary circuit for nullifying the controlling effect produced by said means on said signal controlling circuit; a relay for controlling said auxiliary circuit; and a circuit controlled jointly by the track relays of the block protected by said signal and of the following block for energizing said relay, said last-mentioned circuit being established when the first block is occupied by a train and the second block is unoccupied.

5. In a signaling system for railways, in combination: a stretch of trackway divided into track circuited blocks each having a track relay; a signal for governing traiiic in one direction through said blocks; a circuit for controlling said signal; means controlled by the track relay of the block following the block protected by said signal for controlling said signal controlling circuit; means for nullifying the controlling eflect produced by the said means on said signal controlling circuit; the initial operation of said last-mentioned means being controlled jointly by the track relays of the block protected by said signal and the following block; and means for holding said last-mentioncd means in its operated condition while the track relay of said following block is deenergized.

In testimony whereof I affix my signature in presence of two witnesses.

RONALD A. McCANN.

Witnesses:

A. HERMAN WEGNER, R. L. KISTLER.

Copies 01 this patent may be obtained for five cents each, by addressing the Gominissionex oi Patents. Washington, D. Q."

a pick-up circuit for said auxil-- 

